Carroll Mary F, Hardy Kevin J, Burge Mark R, Schade David S
Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131, USA.
Diabetes Technol Ther. 2002;4(5):595-605. doi: 10.1089/152091502320798213.
This study was designed to assess the frequency of the dawn phenomenon in patients with type 2 diabetes. A secondary aim was to examine the influence of varying treatment regimens on the frequency of the dawn phenomenon. The dawn phenomenon was defined as a rise in plasma glucose levels of > or = 0.5 mmol/L (10 mg/dL) between 0500 and 0900 h occurring after a growth hormone surge of > or = 5 microg/L. Sixteen subjects (six men, 10 women) with type 2 diabetes were studied overnight on their current mode of therapy in the General Clinical Research Center. Additionally, six of these subjects were restudied in random order after each of the following three therapeutic regimens: (1) 6 weeks of glipizide, (2) 6 weeks of bedtime NPH insulin, and (3) 3 days of intensive insulin therapy with multiple injections of regular insulin followed by assessment during overnight intravenous infusion of insulin. Thus, a total of 34 overnight studies were performed under various treatment conditions to provide an approximate frequency of the dawn phenomenon in type 2 diabetes. Blood was drawn every 30 min between midnight and 0800 h for measurement of glucose, insulin, C-peptide, and growth hormone levels. Additional counterregulatory hormone levels were determined during 24 of the studies, and the integrity of growth hormone secretion in response to insulin-induced hypoglycemia was assessed in 12 of the 16 patients. The subjects were aged 51 +/- 15 years with a body mass index of 31 +/- 5 kg/m(2) and a mean glycosylated hemoglobin of 8.1 +/- 1.2%. The dawn phenomenon occurred in only one of 34 (3%) studies. Moreover, the four different treatment regimens did not affect the frequency of occurrence of the dawn phenomenon. Ten of the 12 patients tested failed to secrete growth hormone in response to insulin-induced hypoglycemia. These data suggest that the dawn phenomenon is unusual in type 2 diabetes. Previously reported high prevalence rates in studies using similar sample size may be attributable to a Biostator-induced artifact. Decisions regarding therapies for type 2 diabetes should not be based on the assumption that the dawn phenomenon routinely causes early morning hyperglycemia.
本研究旨在评估2型糖尿病患者黎明现象的发生频率。次要目的是研究不同治疗方案对黎明现象发生频率的影响。黎明现象定义为在生长激素激增≥5μg/L之后，于05:00至09:00之间血浆葡萄糖水平升高≥0.5 mmol/L（10 mg/dL）。16名2型糖尿病患者（6名男性，10名女性）在综合临床研究中心按照其当前治疗模式进行了过夜研究。此外，其中6名受试者在接受以下三种治疗方案中的每一种后，再按照随机顺序重新进行研究：（1）6周的格列吡嗪治疗；（2）6周的睡前中效胰岛素治疗；（3）3天的强化胰岛素治疗，多次注射正规胰岛素，随后在胰岛素过夜静脉输注期间进行评估。因此，在各种治疗条件下共进行了34次过夜研究，以得出2型糖尿病患者黎明现象的大致发生频率。在午夜至08:00之间每隔30分钟采集一次血液，用于测量葡萄糖、胰岛素、C肽和生长激素水平。在24次研究中还测定了其他对抗调节激素水平，并在16名患者中的12名中评估了胰岛素诱导低血糖后生长激素分泌的完整性。受试者年龄为51±15岁，体重指数为31±5 kg/m²，平均糖化血红蛋白为8.1±1.2%。在34次研究中仅1次（3%）出现了黎明现象。此外，四种不同的治疗方案并未影响黎明现象的发生频率。在接受测试的12名患者中，有10名对胰岛素诱导的低血糖未分泌生长激素。这些数据表明，黎明现象在2型糖尿病中并不常见。之前在使用类似样本量的研究中报告的高患病率可能归因于生物人工肾引起的假象。关于2型糖尿病治疗的决策不应基于黎明现象通常会导致清晨高血糖这一假设。
